Storm water separator system

ABSTRACT

A storm water separator system having side walls constructed from sheet piling to enable installation within a small footprint and in poor soil conditions. The separator system has an upper bypass chamber and a lower treatment chamber with a diffuser directing inflowing water down into the lower chamber. A flow control orifice between the two chambers near an outlet orifice in the side wall controls the quantity of flow through the lower chamber. Excess flow bypasses treatment and passes through the upper chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/715,067, filed Nov. 17, 2003.

FIELD OF THE INVENTION

This invention relates to a separator system for treating storm waterand, in particular, a separator system for the entrainment of floatingmatter and sediment.

BACKGROUND OF THE INVENTION

Storm water sewer systems typically include separator systems forreducing the amount of sediment and/or oils or other hydrocarbonspresent in the storm water. Because most storm water sewer systemsrelease the storm water into a natural watercourse, such as a river, thesediments and oils can have a negative environmental impact upon thearea. Sediments will tend to build up a delta and other barriers thatimpact the flow dynamics of the watercourse, thereby impacting uponaquatic life. Therefore, separator systems are placed throughout thestorm water sewer system.

Among known separator systems are hydrodynamic separators. Some of thedrawbacks of hydrodynamic separators include their low capacity, highcost, and required maintenance.

An alternative separator system is a multi-chambered separator system.Known multi-chambered separator systems have difficulty dealing withhigh flow rate storm water. These systems encounter re-suspensionproblems during high flow occurrences wherein previously capturedsediment is remixed or pooled floating hydrocarbons are remixed. Somesystems attempt to address this problem by completely bypassingentrainment during a high flow event and allowing full untreated flowout of the system.

Another drawback with known systems is their large footprint. Thesystems are located underground and require significant excavation toconstruct, which present difficulties in areas with limited space andwith utilities or other structures in the immediate area. A relatedproblem is that existing systems are difficult to accommodate in poorsoil conditions, such as excessively soft wet soil.

SUMMARY OF THE INVENTION

The present invention provides a separator system capable ofinstallation within a small footprint and in poor soil conditions as aresult of the use of sheet piling to establish the sidewalls of theseparator system.

In one aspect, the present invention provides a separator system thatincludes a tank having a bottom and at least one sidewall, the at leastone sidewall including sheet piling, the tank including a mid-deckdefining an upper chamber and a lower chamber within the tank, thesidewall having an inlet orifice and an outlet orifice within the upperchamber and proximate the mid-deck; and a diffuser located proximate theinlet orifice, the diffuser providing fluid communication between theupper chamber and the lower chamber through the mid-deck, wherein themid-deck defines a flow control orifice disposed proximate the outletorifice, the flow control orifice providing fluid communication betweenthe upper chamber and the lower chamber.

In another aspect, the present invention provides a storm waterseparator system including at least one sidewall formed from sheetpiling, the at least one sidewall defining the perimeter of a tank and amid-deck defining an upper chamber and a lower chamber within the tank.The sidewall defines an inlet orifice and an outlet orifice within theupper chamber and proximate the mid-deck and the mid-deck includes adiffuser located proximate the inlet orifice for providing fluidcommunication between the upper chamber and the lower chamber throughthe mid-deck. The mid-deck also includes a flow control orifice disposedproximate the outlet orifice for providing fluid communication betweenthe upper chamber and the lower chamber.

In yet another aspect, the present invention provides a method ofconstructing a storm water separator system. The method includes stepsof driving sheet piling into soil to form at least one sidewall, the atleast one sidewall defining a perimeter of the storm water separatorsystem, and excavating soil from within the perimeter to create a tank.The method further includes steps of back filling the tank with at leasta layer of rock, pouring a concrete slab atop the rock to form a bottomsurface of the tank, defining an inlet orifice and an outlet orificewithin the sidewall, and creating a mid-deck spanning the sidewalls anddisposed adjacent and below the inlet orifice and the outlet orifice.The mid-deck divides the tank into an upper chamber and a lower chamber,and the mid-deck includes a first orifice located proximate the inletorifice for providing fluid communication between the upper chamber andthe lower chamber through the mid-deck, and a second orifice disposedproximate the outlet orifice for providing fluid communication betweenthe lower chamber and the upper chamber.

Other aspects and features of the present invention will become apparentto those ordinarily skilled in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made, by way of example, to the accompanyingdrawings which show an embodiment of the present invention, and inwhich:

FIG. 1 shows a cross-sectional side view of an embodiment of a separatorsystem according to the present invention;

FIG. 2 shows a top plan view of the separator system;

FIG. 3 shows an interior plan view from above a mid-deck of theseparator system;

FIG. 4 shows a base plan view from below the mid-deck of the separatorsystem;

FIG. 5 shows a top view of an embodiment of a diffuser for use in theseparator system;

FIG. 6 shows a cross-sectional front view of the diffuser;

FIG. 7 shows a side view of the diffuser;

FIG. 8 shows an orthographic view of the diffuser; and

FIG. 9 shows a cross-sectional view of a collar in use with a flowcontrol pipe.

Similar numerals are used in different figures to denote similarcomponents.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The highest sediment and oil concentration occurs in the first 10 to 15mm of rainfall, i.e. the “first flush” of storm runoff, as the rainwaterdraws in any deposits of material found on the ground surface andflushes them into the storm sewer system. Therefore, it is especiallydesirable to treat this first flood of rainwater effectively. Later inthe rainstorm the concentration of pollutants in the runoff is typicallymuch lower, and therefore the treatment of storm sewer water later inthe storm event is less critical.

Reference is first made to FIGS. 1 through 4. FIG. 1 shows across-sectional side view of an embodiment of a separator system 10according to the present invention. FIG. 2 shows a top plan view of theseparator system 10. FIG. 3 shows an interior plan view from above amid-deck 16 of the separator system 10. FIG. 4 shows a base plan viewfrom below the mid-deck 16 of the separator system 10.

The separator system 10 includes a tank 12 having sidewalls 14constructed of sheet piling. The tank 12 includes the mid-deck 16dividing the tank 12 into an upper chamber 18 and a lower chamber 20.The tank 12 also includes a bottom 22.

In one embodiment the sheet piling is steel sheet piling, although othertypes of sheet piling may be employed as appropriate to a particularapplication, including but not limited to vinyl sheet piling, fibreglasssheet piling, and others. Although the present embodiment employs Z-typesheet piling, other types may also be used including but not limited toU-type and flat-type. The present embodiment uses a single jaw interlockto couple the sheets of sheet piling together, although it will beunderstood that other interlocks may be used, including but not limitedto ball and socket, double jaw, double hook, thumb and finger, and hookand grip.

The use of sheet piling in creating the sidewalls 14 assists inminimizing the footprint of the separator system 10 and the impact thatinstallation has upon the surrounding environment. The sheet piling isdriven to a depth well below the bottom 22 of the tank 12. Once thesheet piling has been driven into place in the configuration of thecircumference of the tank 12, then the interior of the tank 12 isexcavated to a base below the location of the bottom 22. As theexcavation proceeds, appropriate bracing may be placed around theinterior of the side walls 14 to aid against inward deflection of thesheet piling.

In one embodiment, the base of the excavated area is then back filledwith a layer of pit run and a layer of washed rock. The bottom 22 of thetank is established by pouring a concrete slab 36. The concrete slab 36is poured to incorporate a seepage mechanism, which, in one embodiment,is a pressure relief pipe 38. The pressure relief pipe 38 provides fluidcommunication between the interior of the tank 12 and the ground belowthe concrete slab 36 to allow for limited drainage or seepage of fluidout of the tank 12 and into the ground. The pressure relief pipe 38 mayfeature a plurality of perforations (not shown) throughout its lower endin the vicinity of the washed rock layer or the pit run layer. Thislower end may be wrapped in a filter cloth to prevent clogging of theperforations. The top of the pressure relief pipe 38 may be positionedabove the surface of the bottom 22 to prevent significant collectedsediment on the bottom 22 from entering the pressure relief pipe 38.

The sidewalls 14 define an inlet orifice 24 and an outlet orifice 26.The inlet orifice 24 and the outlet orifice 26 are disposed within theupper chamber 18 portion of the sidewalls 14 and are located proximatethe mid-deck 16. In one embodiment, the inlet orifice 24 and the outletorifice 26 are both adjacent the mid-deck 16. The mid-deck may beconstructed of any suitable material and secured to the sidewalls 14 inany suitable manner, as will be appreciated by one of ordinary skill inthe art. In one embodiment, the mid-deck is formed from a decking uponwhich a layer of reinforced concrete is cured.

The upper end of the tank 12 is closed by a top deck 44. The top deck 44seals the upper end of the tank 12 and is secured to the upper ends ofthe sidewalls 14. The top deck 44 may incorporate a grating forcollecting runoff from a gutter or roadway. The top deck 44 and themid-deck 16 may also include access hatches 46 to permit access to theinterior of the tank 12.

The inlet orifice 24 and the outlet orifice 26 may have an inlet pipe 28and an outlet pipe 30, respectively, extending outwards therefrom. Theinlet pipe 28 and the outlet pipe 30 are each intended to be coupled toexisting in-ground sewer pipes. In one embodiment, the inlet pipe 28 andthe outlet pipe 30 are constructed of steel, the in-ground sewer pipesare concrete, and they are coupled together using modular seals.

The separator system 10 further includes baffles 34 within the lowerchamber 20. The baffles 34 extend upwards from the bottom 22 of the tank12 and are positioned transverse to the flow direction between the inletorifice 24 and the outlet orifice 26. It will be understood that thebaffles 34 assist in encouraging settlement of sediment within the lowerchamber 20 on the bottom 22 of the tank 12. The baffles 34 may beconstructed of any suitable material including, but not limited, toconcrete and rebar.

The separator system 10 includes a diffuser 32 located proximate themouth of the inlet orifice 24. The diffuser 32 provides fluidcommunication between the upper chamber 18 and the lower chamber 20. Inparticular, the diffuser 32 directs water flow incoming from the inletorifice 24 down into the lower chamber 20.

Reference is now made to FIGS. 5 through 8. FIG. 5 shows a top view ofthe diffuser 32. FIG. 6 shows a cross-sectional front view of thediffuser 32. FIG. 7 shows a side view of the diffuser 32. FIG. 8 showsan orthographic view of the diffuser 32.

The diffuser 32 includes a front wall 100, a back wall 102, andsidewalls 104 assembled in a box shape. The upper end of the back wall102 defines a partial circular cutout 106 that registers with thediameter of the inlet pipe 28. The walls 100, 102, and 104 extenddownwards. The sidewalls 104 each include a top portion 108 that extendsdownwards and a bottom portion 110 that meets the lower end of the topportion 108 and flares outwards and downwards, as shown in FIG. 6.

The diffuser 32 includes vanes 112 (shown individually as 112 a, 122 b,. . . , 112 e) formed by interior walls extending between the front wall100 and the back wall 102 and spaced apart from the side walls 104. Eachof the vanes 112 includes an upper portion 114 and a lower portion 116.The upper portion 114 of each vane 112 is parallel to the top portion108 of the sidewalls 104. The lower portions 116 of at least some of thevanes 112 are flared or angled outwardly so as to direct a portion ofthe fluid flow through the diffuser 32 outwards and downwards, therebyspreading or diffusing the fluid flow descending through the diffuser 32into the lower chamber 20 (FIG. 1).

The lower portions 116 of vanes 112 closer to the bottom portions 110 ofthe sidewalls 104 are angled or flared more acutely than the lowerportions 116 of vanes 112 located near the centreline of the diffuser32, equidistant between the two sidewalls 104.

The diffuser 32 aids in transitioning the storm water flow from theinlet pipe 28 into the lower chamber 20 without causing excessturbulence. Accordingly, the diffuser 32 lessens the possibility thatturbulence from inflowing storm water will re-suspend particulatematter, i.e. sediment, that was collected along the bottom 22 (FIG. 1)of the lower chamber, or re-mix any floating matter, such as oils orother hydrocarbons.

The diffuser 32 may include an outwardly extending flange 118 formounting the diffuser 32 to the mid-deck 16 (FIG. 1).

Referring again to FIGS. 1 through 4, the mid-deck 16 features a flowcontrol orifice 40. The flow control orifice 40 provides fluidcommunication between the upper chamber 18 and the lower chamber 20 andis located proximate the outlet orifice 26. The flow control orifice 40may be defined by a flow control pipe 42 fitted into the mid-deck 16.The flow control pipe 42 extends downwards into the lower chamber 20 soas to prevent the uptake of materials that may be floating within thelower chamber 20 against the undersurface of the mid-deck 16. In oneembodiment, the upper end of the flow control pipe 42 includes aninwardly extending flange having a set of bolt holes (not shown).Collars of various sizes may be attached to the inwardly extendingflange using bolts, as illustrated by the cross-sectional view of acollar 99 in use with the flow control pipe 42 shown in FIG. 9. Thecollars customize the size of the flow control orifice 40 for aparticular installation.

The inner diameter of the flow control orifice 40 determines the balancebetween storm water flows through the lower chamber 20 and through theupper chamber 18 when a bypass situation is encountered during highflows. High volume flows are initially directed into the lower chamber20 by the diffuser 32 during the beginning of a rainstorm. When thelower chamber 20 is at capacity, the rate of inflow to the lower chamber20 through the diffuser 32 is governed by the rate of outflow from thelower chamber 20 through the flow control orifice 40. The size of theflow control orifice 40 thus determines the extent to which storm wateris treated in the lower chamber 20 during high flow conditions. Anyexcess inflow from the inlet pipe 28 through the inlet orifice 24bypasses the diffuser 32 and flows to the outlet orifice 26 over themid-deck 16. Therefore, even under high flow conditions, a portion ofthe incoming storm water is treated through the lower chamber 20, andthe volume of that portion is determined by the diameter of the flowcontrol orifice 40. Accordingly, the separator system 10 treats the“first flush” effectively while allowing for bypass of later high flowvolume. Even under bypass conditions, a portion of the storm water flowis treated by the lower chamber 20. Moreover, the portion of the stormwater that enters the lower chamber 20 tends to be the flow proximatethe bottom of the inlet pipe 28, which is the flow that is most likelyto contain sediment material requiring treatment in the lower chamber20.

Referring still to FIGS. 1 through 4, the separator system 10 mayinclude an oil retrieval pipe 48 for extracting oils and otherhydrocarbons that may be pooled on the surface of the water collected inthe lower chamber 20. The oil retrieval pipe 48 extends above the uppersurface of the mid-deck 16 and provides for fluid communication betweenthe upper chamber 18 and the lower chamber 20. It provides an accesspoint through which a hose may be inserted in order to pump out the oilsand other hydrocarbons.

It will be understood that, although embodiments of the presentinvention discussed herein show the tank 12 in a rectangular shape,other shapes are also possible, including but not limited to circles,ellipses, square and other shapes. Sheet piling of a type appropriate tothe configuration of the tank should be selected.

Those of ordinary skill in the art will also appreciate that variousmodifications may be made to customize the separator system 10 to aparticular installation. For example, the number and placement of thebaffles 34 may depend upon the expected type and quantity of sedimentpresent in the storm water, which depends upon the environment in whichthe separator system 10 is used. In some embodiments, no baffles 34 maybe needed. Other modifications will be within the understanding of thoseof ordinary skill in the art having regard to the foregoing description.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Certainadaptations and modifications of the invention will be obvious to thoseskilled in the art. Therefore, the above discussed embodiments areconsidered to be illustrative and not restrictive, the scope of theinvention being indicated by the appended claims rather than theforegoing description, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

1. A separator system, comprising: a tank having a bottom and at leastone sidewall, said at least one sidewall including sheet piling, saidtank including a mid-deck defining an upper chamber and a lower chamberwithin said tank, said sidewall having an inlet orifice and an outletorifice within said upper chamber and proximate said mid-deck; and adiffuser located proximate said inlet orifice, said diffuser providingfluid communication between said upper chamber and said lower chamberthrough said mid-deck, wherein said mid-deck defines a flow controlorifice disposed proximate said outlet orifice, said flow controlorifice providing fluid communication between said upper chamber andsaid lower chamber.
 2. The separator system claimed in claim 1 whereinsaid diffuser includes at least one wall defining a top opening and abottom opening, said top opening being located proximate said inletorifice and said bottom opening being in communication with said lowerchamber.
 3. The separator system claimed in claim 2 wherein said inletorifice has a flow direction and said diffuser further includes aplurality of spaced apart vanes attached to said at least one wall anddisposed parallel to said flow direction for dispersing a fluid flowmoving from said top opening to said bottom opening.
 4. The separatorsystem claimed in claim 3 wherein said vanes are spaced apart further atsaid bottom opening than at said top opening.
 5. The separator systemclaimed in claim 1 further including at least one baffle extendingupwards from said bottom within said lower chamber between said diffuserand said flow control orifice.
 6. The separator system claimed in claim1, wherein said flow control orifice is defined by an interior diameterof a flow control pipe extending from said mid-deck downwards into saidlower chamber.
 7. The separator system claimed in claim 6, wherein saidflow control pipe includes a collar defining said interior diameter,said collar being removably attached to said flow control pipe.
 8. Theseparator system claimed in claim 1, wherein said at least one sidewallincludes four sidewalls in a rectangular formation.
 9. The separatorsystem claimed in claim 1, wherein said sheet piling includes steelsheet piling.
 10. The separator system claimed in claim 9, wherein saidsteel sheet piling includes Z-type steel sheet piling.
 11. The separatorsystem claimed in claim 1, further including an oil extraction pipeproviding fluid communication between said lower chamber and said upperchamber, said oil extraction pipe extending upwards from said mid-deckinto said upper chamber.
 12. The separator system claimed in claim 1,further including an inlet pipe coupled to said at least one side walland defining said inlet orifice and an outlet pipe coupled to said atleast one side wall and defining said outlet orifice, said inlet pipeand said outlet pipe being adapted for attachment to sewer pipelines.13. A storm water separator system, comprising: at least one sidewallformed from sheet piling, the at least one sidewall defining theperimeter of a tank; a mid-deck defining an upper chamber and a lowerchamber within said tank, wherein said sidewall defines an inlet orificeand an outlet orifice within said upper chamber and proximate saidmid-deck and wherein said mid-deck includes a diffuser located proximatesaid inlet orifice for providing fluid communication between said upperchamber and said lower chamber through said mid-deck, and a flow controlorifice disposed proximate said outlet orifice for providing fluidcommunication between said upper chamber and said lower chamber.
 14. Theseparator system claimed in claim 13, wherein said at least one sidewallincludes four sidewalls in a rectangular formation.
 15. The separatorsystem claimed in claim 13, wherein said sheet piling includes steelsheet piling.
 16. The separator system claimed in claim 15, wherein saidsteel sheet piling includes Z-type steel sheet piling.
 17. A method ofconstructing a storm water separator system, comprising steps of:driving sheet piling into soil to form at least one sidewall, said atleast one sidewall defining a perimeter of said storm water separatorsystem; excavating soil from within said perimeter to create a tank;back filling said tank with at least a layer of rock; pouring a concreteslab atop said rock to form a bottom surface of said tank; defining aninlet orifice and an outlet orifice within said sidewall; and creating amid-deck spanning the sidewalls and disposed adjacent and below saidinlet orifice and said outlet orifice, wherein the mid-deck divides saidtank into an upper chamber and a lower chamber, and wherein saidmid-deck includes a first orifice located proximate said inlet orificefor providing fluid communication between said upper chamber and saidlower chamber through said mid-deck, and a second orifice disposedproximate said outlet orifice for providing fluid communication betweensaid lower chamber and said upper chamber.
 18. The method claimed inclaim 17, wherein said step of creating said mid-deck comprises forminga decking and curing reinforced concrete upon said decking.
 19. Themethod claimed in claim 17, wherein said step of driving sheet pilingcomprises driving steel sheet piling to a depth below said bottomsurface.
 20. The method claimed in claim 17, wherein said step ofcreating said mid-deck includes mounting a diffuser within said firstorifice and attaching a flow control collar within said second orifice.